1-Substituted biguanides for treating gastrointestinal hyperacidity or ulceration

ABSTRACT

A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals employing 1-substituted biguanides is described. Compounds of this type which also display antihypertensive and CNS depressant properties are also disclosed.

United States Patent Diamond et a1.

l-SUBSTITUTED BIGUANIDES FOR TREATING GASTROINTESTINAL HYPERACIDITY ()R ULCERATION Inventors: Julius Diamond, Lafayette Hill;

George H. Douglas, Paoli; Bernard J. Burns, Philadelphia, all of Pa.

Assignee: William H. Rorer, Inc., Fort Washington, Pa.

Filed: May 12, 1971 Appl. No.: 142,794

Related US. Application Data Division of Ser. No. 89,005, Nov. 12, 1970, abandoned.

US. Cl. 424/326 Int. Cl A6lk 27/00 Field of Search 424/326 References Cited UNITED STATES PATENTS l/l968 Bernstein et al 424/326 3,456,059 7/1969 Wick et al. 424/326 FOREIGN PATENTS OR APPLICATIONS 40-11628 9/1965 Japan 424/326 OTHER PUBLICATIONS Brit. J. Pharmacol, (1948) 3, 346, pp. 346-51.

Antibiotics and Chemotherapy I], 572-582 (1961).

Primary ExaminerFrederick E. Waddell Attorney, Agent, or Firm-James A. Nicholson [57] ABSTRACT A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals employing 1- substituted biguanides is described. Compounds of this type which also display anti-hypertensive and CNS depressant properties are also disclosed.

15 Claims, No Drawings l-SUBSTITUTED BIGUANDIES FOR TREATING GASTROINTESTINAL HYPERACIDITY OR ULCERATION CROSS REFERENCE TO RELATED APPLICATIONS This is a division of co-pending application Ser. No. 89,005, filed Nov. l2.l970, now abandoned.

SUMMARY OF THE INVENTION This invention describes new l-substituted biquanide compounds and processes for their preparation. This invention further provides valuable pharmaceutical preparation which contain l-substituted biquanide compounds as active gastric antisecretory and spasmolytic agents. A method for the treatment of gastrointestinal disorders and diseases is also described. The compounds of this invention also possess an effective degree of antihypertensive and CSN depressant.

BACKGROUND OF THE INVENTION The pharmaceutical compositions which have been used as gastric antisecretory and spasmolytic agents have been such as atropine, homatropine. propantheline bromide, dicyclomine hydrochloride and other compounds which are structurally dissimilar to the biquanides of this invention. Due to the antlcholinergic properties of these compounds they are known to produce undesirable side effects such as mydriasis, xerostomia, cyclopegia and other unwanted effects.

There have been a number of l-aryl and aralykyl biquanides described in the literature. They have been proposed for use as antidiabetics, anoerexigenic or antimalarial agents. J. H. Burn and J. R. Vane, however, in The Brit J. Pharmacol. (1948), 31346-9 tested l-(pchlorophenyl)biquanide and l-(p-methoxyphenyl)- biquanide for their ability to reduce gastic secretion. Their findings determined that little or no reduction of gastric secretion was associated with these compounds. Contrary to this belief:

We have unexpectedly found that the l-substituted biquanides of this invention are valuable pharmacologic agents which possess useful gastric antisecretory and spasmolytic properties.

We have also found that the compounds of this invention are substantially free of the anticholinergic side'effects which accompany gastric antisecretory and spasmolytic agents.

We have further found that the compounds of this invention have a low order of toxicity.

We have still further found a simple and effective method for treating gastrointestinal disorders and diseases, such as duodenal and peptic ulcers.

We have found that the l-substituted biquanides of this invention also have an effective degree of antihypertensive and CNS depressant.

DESCRIPTION AND PREFERRED EMBODIMENT This invention describes a class of novel chemical compounds which contain a phenyl, substituted phenyl. aralkyl or substituted aralkyl radical attached to a hiquanide chain. This invention further describes its non-toxic pharmaceutically acceptable salts and the method of preparing the instant compounds.

This invention also describes a new method of treating gastrointestinaldisorders and diseases and of gastrointestinal therapeutic compositions, which comprises the administration of a l-substituted biquanide compound having the structural formula as shown in FIG. I.

5 l l a un -na-c-na-c-nfl where:

n is O-l; R is hydrogen. or

loweralkyl; R R R R & R. may be the same or different and are hydrogen, loweralkyl. nitro, amino,

NR mt ll I R NI-IC-hlIIrCb-Nll 6 where: 1:

R and R are hydrogen, halo, haloloweralkyl or alkoxy;

R is hydrogen,

haloloweralkyl, hydroxy, nitro, or halo provided both R and R are not both hydrogen at the same time.

The most preferredcompounds for a method of treating gastrointestinal disorders and diseases and for use in gastrointestinal compositions embrace those compounds of structural formula II. where:

R R and R are hydrogen. chloro. bromo, fluoro or trifluoromethyl, provided R is not' chloro when both R and R are hydrogen. In the descriptive portions of this invention, the following definitions apply:

The term lower alkyl refers to an alkyl hydrocarbon group containing from 1 to about 8 carbon atoms which may be straight chained or branched.

The acyl radical may be any organic radical derived from an organic acid by its removal of the hydroxyl group such as acetyl, propionyl. benzoyl. etc.

The lower alkoxy" radical signifies an alkoxy group containing from 1 to about 8 carbon atoms which can be straight chained or branched.

The compounds of structural formula I are also useful in the treatment of hypertensive and CNS depressant disorders. The more preferred compounds used in a method of treating hypertensive disorders are those described by HG. ll where R, is hydrogen. The most preferred compounds are those described by FIG. ll where: R and R are fluoro, chloro, bromo or trifluoromethyl. This invention describes new chemical compounds which are generically described by the structural formula as shown in FIG. I. where:

n is -1; R is hydrogen or lower alkyl;

R R R R & R may be the same or different and are: haloloweralkyl, hydroxy, cyanato. carboxy, carbalkoxy, diloweralkylsulfonamido. phenoxy, halophenoxy, acyloxy, haloloweralkoxy or phenyl, halophenyl;

R R R & R may also be fluoro. bromo, chloro. nitro, amino, dialkylamino or cyano; when R & R are substituted then R., may also be hydrogen, fluoro, bromo. chloro. iodo, nitro or cyano;

R and R may be hydrogen; and

R and R may be hydrogen, when n is I provided there are fewer than 4 hydrogens present.

The more preferred compounds of this invention embrace those compounds of structural formula I where:

n is 0.

The most preferred compounds of this invention embrace those compounds of structural formula ll where n is 0 and R and R are LII iodo, chloro, bromo. fluoro or nitro; and

R is hydrogen.

halo, nitro, or trifluoromethyl.

It is well known in the pharmacological arts that nontoxic acid addition salts of pharmacologically active amine compounds do not differ in activities from their free base. The salts merely provide a convenient solubility factor.

The amines of this invention may be readily converted to their non-toxic acid addition salts by customary methods in the art. The non-toxic salts of this invention are those salts the acid component of which is pharmacologically acceptable in the intended dosages; such salts would include those prepared from inorganic acids, organic acids. higher fatty acids, high molecular weight acids, etc. and include such as:

hydrochloric acid. succinic acid.

hydrobromic acid, glycolic acid. sulfuric acid. lactic acid, nitric acid. salicylic acid.

bcnzoic acid.

phosphoric acid.

nicotinic acid.

mcthanc sulfonic acid.

hcnzenc sulfonic acid, phthalic acid. acetic acid. stcaric acid. propiunic acid olcic acid. malic acid. abictic acid. etc.

where:

n is also 2; R is loweralkenyl.

' cycloloweralkyl, haloloweralkyl,

arloweralkyl or aryl;

R2, R3, R4, R5 & R; iS

loweralkenyl, aminoloweralkyl, alkylaminoloweralkyl, hydroxyloweralkyl, mercapto, loweralkylthio, loweralkylsulfinyl, loweralkylsulfonyl, sulfonamido, loweralkoxyloweralkyl, mercaptoloweralkyl. loweralkylmercaptoloweralkyl, arloweralkylmercaptoloweralkyl, arloweralkyl, arloweralkenyl, halobenzyl anilino, loweralkoxyphenyl, biphenylyl. phenoxy, benzyloxy. a polyfluoro substituted group such as trifluoromethylsulfonyl. trifluoroacetyl, trifluoroacetoxy,

trifluorocarbomethoxy, di-(trifluoromethylamino)sulfonyl. di-(trifluoromethylamino)carbonyl. or B,B-difluorovinyl.

The products of this invention can contain an asymetric carbon atom when n=l. For this reason they may be obtained as racemic mixtures or as dextro and levorotatory isomers. These may be separated by any of the various methods of resolution. A method that may be employed is combining the racemic compound with an optically active compound. for example. by salt formation. Two products are then obtained. If the instant biguanides are added to an optically active acid, such as or (-)-tartaric acid, then the salts produced possess different properties and different solubilities and can be separated by fractional crystallization. When the salts have been separated by repeated crystallization, the acid is split off and the pure dor I- biguanide compound is obtained. It is to be understood that these optical isomers are embraced within the extent of this invention.

Representative compounds of this invention which are particularly useful are as follows:

l-(p-trifluormethylphenyl)biguanide l'(p-trifluoromethyoxyphenyl)biguanide l-(p-dimethylsulfamylphenyl)biguanide l-(p-trifluoromethylbenzyl)biguanide l-( 2.6-dichlorophenyl )biguanide l-(2,6-dibromophenyl)biguanide l-(2,4,6-trichlorophenyl)biguanide l-(2.6-dichlorobenzyl)biguanide l-(2.4,6-trichlorobenzyl)biguanide l-(2,6-dichloro-4-hydroxyphenyl)biguanide l-(2,6-dichloro-a-methylbenzyl)biguanide l-(3,S-ditrifluoromethylphenyl)biguanide l-(3,4,5-trimethoxyphenyl)biguanide l-(2,4,6-trimethoxyphenyl)biguanide l-(3,5-dichloro-4-methoxyphenyl)biguanide l-(2,3,4,6.-tetrafluorophenyl)biguanide l-(2.3.4.5-tetrafluorophenyl)biguanide l-(2,6-dibromo-4-trifluoromethylphenyl)biguanide l-(2,4,6-tribromophenyl)biguanide l-(2,6-dibromo-4-chlorophenyl)biguanide l 2,6-dichloro-4-bromophenyl )biguanide l-(2.6-dichloro-4-trifluoromethylphenyl)biguanide 2,4-dichloro-o-thiocyanatophenyl )biguanide -(2,6-dibromo-4-fluorophenyl)biguanide -(2,6-dichloro-4-thiocyanatophenyl)biguanide -(2,6-dichloro-4-fluorophenyl)biguanide (2,6-dibromo-4-iodophenyl)biguanide .6-dichloro-4-nitrophenyl)biguanide -(2,4dichloro-6-nitrophenyl)biguanide -(2,6-dinitro-4-chlorophenyl)biguanide -(2,6-dibromo-4-nitrophenyl)biguanide -(2,6,4-trichloro-4-biphenyl)biguanide -(2,6-dichloro-4-phenoxyphenyl)biguanide -(2,6.4'-trichloro-4-phenoxyphenyl)biguanide l-(2,6-dibromo-4-(4'-chlorophen0xy)phenyl)- biguanide l-( 2.6-dibromo-4-phenoxyphenyl)biguanide l-(2,6-dibromo 4'-chloro-4-biphenyl)biguanide l-(2,4-dichlorophenyl)biguanide l-(2,3-dichlorophenyl)biguanide l-(2,5-dichlorphenyl)biguanide l-(2.4-dibromophenyl)biguanide The compounds of this invention may be prepared by the following general procedures:

Condensation of cyanoguanide and an aryl or aralkylamine in the presence of an equimolar amount of a mineral acid results in the corresponding aryl or arnlkylbiguanide.

The following reaction equation illustrates this synthesis:

it II a (Ti-na H! cam-cam E i a t 3 2 11 mt int a ll a (c) tnt-c-tnt-c-inr int -52.. s r a, 1

R R3 2 m1 i a (ii -mu N}l-C-NH R5 is a where n, R R R R R & R are as described above. and HX is a mineral acid.

The reaction is preferably carried out on the aryl or aralkylamine salt either in a polar medium or neat and using increased temperatures. The salt used may be any acid addition amine salt but preferably the salt of a mineral acid. The polar medium may be aqueous. partially aqueous or a non-asueous solution. it is convenient to choose a solvent that will reflux at the desired reaction temperature. The more preferred solvents are water or alcohol but other solvents may be used such as DMSO, diethyleneglycol, ethyleneglycol. tetrahydrofuran. dimethylformamide, etc. The reaction should also be carried out at a temperature which is high enough so that condensation takes place readily, but not sufficient to decompose the biguanide formed. The reaction temperature can vary from room temperature to about 250C although it is preferable to run the reaction at temperatures from about 50C to C. The biguanide salt which is formed can be converted to the free base with a metal hydroxide or alkoxide solution. The isolation of the desired biguanide can be carried out by any method known in the art.

Appropriately desired end products having various R R R R- and R substituents can be prepared at various stages of synthesis using suitable reactions in order to convert one group to another. Thus, for example, using conventional methods, a halogen group can be treated under Rosenmund Von Brown conditions to the nitrile compound which in turn can be hydrolyzed to a carboxy. A nitro can be reduced to an amino which can be alkylated to the dialkylamino substituent. A hydroxy compound can be prepared by demethylation of a methoxy substituent. A Sandmeyer type reaction can be carried out on an amino compound to intorduce a chloro ,.bromo. xanthate, hydroxyl or alkoxyl group. The xanth ate can then lead to the mercapto by hydrolysis, this in turn can be alkylated to an alkylthio group l -l -(4 '-chlorophenoxy)phenyll I-( 4-trifluorome thylphenyl) biguanide l-(4-bromophenyl )biguanide l-(4-fluorophenyl )biguanide phenyhbiguanide biguanidc l-(4-chlorophenyl )biguanide biguanide l-( 2,6-dichlorophenyl)biguanidc biguanidc l-(4-iodophenyl )biguanide biguanidc l-( 4-nitrophenyl )biguanidc higuanide l-(4'-chloro-4-hiphcnyll hiphenyl )biguanide biguanide l-(4-phenoxyphenyl )biguanide biguanide biguanide I phcnyl lbiguanidc l-(2,4-dichlorophcnyl)biguanide I higuanidc in an analogous manner, chlorination, nitration and thiocyanation can also be carried out to obtain corresponding products. Other reactions known in the art may also be employed.

The starting materials of this invention are either known compounds or their method of preparation is described.

We have found that the compounds of this invention have a useful degree of gastric anti-secretory activity and are effective in reducing the volume and the acidity of the gastric fluid in humans and mammals. Further, these compounds produce a considerable spasmolytic action on the gastrointestinal mulculature, i.e., they reduce the peristaltic action of the gastrointestinal musculature which is manifested by a delay in gastric emptying time.

Until now, the known gastric anti-secretory and gastrointestinal spasmolytic compounds have included such agents as atropine, homatropine, propantheline, dicyclomine, etc. These compounds, however, cause accompanying undesirable anti-cholinergic properties such mydriasis, xerostomia, cyclopegia, etc. We have found that the l-aryl and aralykylbiguanides of this invention are particularly useful as gastric antisecretory agents because they are essentially devoid of these unwanted effects. It should further be noted that these compounds are also characterized by their low acute oral toxicity.

In particular the l-aryl and aralkyl-biguanides as herein described are useful in the treatment of such gastrointestinal disorders and diseases as duodenal ulcer and peptic ulcer.

The instant compounds may be used alone or in combination with other kn'won antacids such as aluminum hydroxide, magnesium hydroxide. magnesium trisilicate, aluminum glycinate. calcium carbonate and the like.

l-( 2,6-dibromo-4-chloroph enyl) l-( 2,6-dichloro-4-hromophcnyl) l-( 2,6-dibromo-4-iodophenyl) l-( 2,6-dibromo-4-nitrophcnyl) l-( 2.4dichloro-6-bromophcnyl) For all these purposes, the biguanides of this invention can be normally administered orally or parenterally. Orally they may be administered as tablets, aqueous or oily suspension, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. The term parenteral as used herein, includes subcutaneous injection, intravenous, intramuscular or intrasternal injecton or infusion techniques.

Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected l-( 2.6-dibromo-4-trifluoromethyll-( 2,4,6-tribromophcnyl )biguanide l-( 2,6-dibromo-4-fluorophenyl) l-( 2,6-dibromo-4-phcnoxyphcnyl) .l-[ 2,6-dibromo-4-( 4'-chlorophenoxy) from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a pharmaceutically elegant and palatable preparation. Tablets which contain the active laryl and aralkylbiguanide ingredient in admixture with non-toxic pharmaceutically acceptable excipients are suitable for the manufacture of tablets. These excipients may be, for example, inert diluents, for example, calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, maize starch or alginic acid; binding agents, for example, starch, gelatin or acacia; and lubricating agents, for example, magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period.

Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with an oil medium, for example, arachis oil, liquid paraffin or olive oil.

Aqueous solutions containing the active l-aryl and aralkyl biguanides form a further embodiment of this invention. Excipients suitable for aqueous suspensions, may be employed if desired. These excipients are suspending agents, for example, sodium carboxymethylcellulose, methyl-cellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidine, gum tragacanth and gun acacia;dispersing or wetting agents may be a naturally occuring phosphatide, for example, lecithin; or condensation products of an alkylene oxide with fatty acids, for example, polyoxyethylene stearate; or condensation products of ethylene oxide with longchain aliphatic alcohols, for example, heptadecaethyleneoxy-cetanol; or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol, for example, polyoxyethylene sorbitol monooleate; or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example, polyoxyethylene sorbitan monooleate. The said aqueous suspensions may also contain one or more preservatives, for example, ethyl, or npropyl, p-hydroxy benzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose.

Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example, arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil, such as liquid paraffin. The oily suspensions may contain a thickening agent, for example, beeswax, hard paraffin or cetyl alcohol. Sweetening agents, such as those set forth above, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid.

Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active ingredient in admixture with a dispersing or wetting agent, suspending or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example, sweetening, flavoring and coloring agents, may also be present.

The compounds of this invention may also be in the form of oil-in-water emulsions. The oily phase may be a vegetable oil, for example, olive oil or arachis oils, or a mineral oil, for example, liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturallyoccurring gums, for example, gum acacia or gum tragacanth, naturally-occuring phosphatides, for example, soya bean lecithin, and esters of partial esters derived from fatty acids and hexitol anhydrides, for example, sorbitan mono-oleate. The emulsions may also contain sweetening and flavoring agents.

ter the minimum effective level which gives relief.

- Thus, in general, the dosages are those that are thera- Syrups and elixirs may be formulated with sweetening agents, for example, glycerol, sorbitol or sucrose. Such formulations may balso contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions may be in the form of a sterile injectable preparation, for example, as a sterile injectable aqueous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example, as an aqueous solution buffered to a pH of 4.0 to 7.0 and made isotonic with sodium chloride.

Further, these compounds may be tableted or otherwise formulated so that for every 100 parts by weight of the compositions, there are present between 5 and 95 parts by weight of the active ingredient. The dosage unit form will generally contain between about 1 mg. and about 500 mg of the active ingredients of this invention. The preferred unit dose is between about 10 mg and about 100 mg.

The dosage regimen in carrying out the methods of this invention is that which insures maximum therapeutic response until improvement is obtained and thereafpeutically effective in the treatment of gastrointestinal disease conditions or symptoms, such as duodenal and peptic ulcer, and in the alleviation of hypertensive disorders. In general, the daily dose can be between about 0.5 mg/kg and mg/kg (preferably in the range of 2-25 mg/kg/day), bearing in mind, of course, that in selecting the appropriate dosage in any specific case. consideration must be given to the patient's weight, general health, age, and other factors which may influence response to the drug.

Various tests in animals have been carried out to show the ability of the compounds of this invention to exhibit reactions that can be correlated with activity in humans. These tests involve such factors as the effect of the l -aryl and aralkylbiguanides on gastric secretion, their spasmolytic effect, their mydriatic effect and determination of their toxicity. [t has been found that the compounds of this invention when tested in the above variety of situations show a marked activity.

One such test is the gastric secretion test. This test is carried out as follows: Shay rats are fasted for 4-8 hours, and water is given ad lib. The rats are selected at random and separated into groups of 10. The animals are treated introduodenally (l.D.) with the test compound or the vehicle immediately subsequent to the ligation of the stomach at the pyloric sphincter. The animals are sacrificed with chloroform at 4 hours postdrug administration, the stomach is removed and its contents are assayed for volume, pH and total acids.

A second gastric secretion test is carried out on the dog. This is outlined in the Handbook of Physiology. Section 6: Alimentary Canal, Volume ll: Secretion. American Physiology Society, Washington, D.C., 1967.

It has been found that the compounds of this invention when subjected to the above gastric secretion tests display marked ability to decrease gastric volume and gastric acidity. These tests are known to correlate well with gastric activity in humans and are standard tests used to determine anti-secretory properties.

To determine the anti-ulcer effectiveness the following test is employed: Male Wiston rats (-150 grams) are fasted for 24 hours, then given reserpine at 5 mg/kg i,p. 24 hours later, the stomachs are removed and examined for ulceration. Ulcers are graded on a 0-4 scale and the number of ulcers is recorded. Pretreatment with the biguanide compounds produces a decrease in ulcer grade and the number of ulcers compared to the control reserpinetreated rats.

Determination of anti-spasmolytic properties can be carried out by the procedure as outlined by D. A. Brodie and S. K. Kundrate in their article entitled Effect of Drugs on Gastric Emptying in Rats," Fed. Proc. 24:7l4 (1965).

Mydriasis is detected by the procedure of R. A. Turner, Screening Methods in Pharmacology, Academic Press. New York, and London, pp. 174-5, 1965. Acute toxicity is calculated according to the standard Litchfield-Wilcoxon procedure.

In view of the results of these tests, the pharmacological data clearly indicates that the l-aryl and aralkylbiguanides of this invention canv be considered to be active gastric anti-secretory and anti-spasmolytic agents which are substantially free of anticholinergic side effects and having a low toxicity.

Tests in animals have also been carried out to show the ability of compounds of this invention to inhibit reactions that can be correlated with hypertensive effects in humans. One such test is outlined by Jacques de Champlain, Lawrence R. Krahoff and Julius Axelrod in Circulation Research XXlllz479 (1968). This testing method is known to correlate well with hypertensive activity in humans and is a standard test used to determine antihypertensive properties. In view of the results of this test, the l-aryl and aralkyl biguanides of this invention can be considered to be active antihypertensive agents.

To determine the CNS depressant effectiveness of the compound of Formula 1, the suppression of spontaneous motor activity is evaluated in normal mice (18-22 g) and immature rats (90-100 g) by a modification of the Dew method: Dews, Brit. J. Pharmacol: 8, 46 (1953). Results of this test indicate that a relative increase in depressant activity is evident.

The following are detailed examples which show the preparation of the compounds of this invention. They are to be construed as illustrations of said compounds and not as limitations thereof.

EXAMPLE 1 l-(p-Trifluoromethoxyphenyl)biguanide dihydrochloride A stirred mixture of 6.3 g. (0.0296 mole) of p-aminophenyltrifluoromethyl ether hydrochloride and 2.49 g. (0.0296 mole) of cyanoguanidine is immersed in a 210C. oil bath for fifteen minutes. The resulting amber glass-like reaction product is dissolved in 100 ml of water, alkalized with 40 percent sodium hydroxide solution, and extracted with 250 ml of ether. The ether layer is backwashed twice with ml of water, dried over sodium carbonate, filtered. and the ether solution made strongly acidic with a saturated ethereal hydrochloric acid solution. The precipitate is collected on a filter, washed twice with 50 ml of anhydrous ether. and dried at 25C/125 mm. Recrystallization from a mix ture of isopropanol and cyclohexane (l:l) gives l-(p-trifluoromethoxyphenyl) biguanide dihydrochloride (m.p. 209-2l 1C).

EXAMPLE 2 l-(p-Trifluoromethylbenzyl)biguanide dihydrochloride A stirred mixture of 6.9 g (0.035 mole) of p-trifluoromethylbenzylamine hydrochloride and 2.9 g (0.035 mole) of cyanoquanidine is immersed in a 180C oil bath for 1 hour. The melt is cooled and dissolved in 35 ml of hot water. The solution is cooled in an ice bath, made alkaline with 40% sodium hydroxide solution, and extracted with 150 ml of ether. The ether layer is dried over potassium carbonate, filtered and the ether solution made strongly acidic with a saturated ethereal hydrochloric acid solution. The precipitate is washed twice with 25 ml of anhydrous ether and recrystallized from a mixture of ethanol and heptane (3:5) to obtain l-(p-trifluoromethylbenzyl)biguanide (m.p. 223-225C.)

EXAMPLE 3 l-(a-Methyl-p-trifluoromethylbenzyl)biguanide dihydrochloride A stirred mixture of 15.5 g (0.0687 mole) ofa-methw yl-p-trifluoromethylbenzylamine hydrochloride and 6.35 g (0.0756 mole) of cyanoguanidine is immersed in a 190C oil bath for 10 minutes. The melt is cooled to room temperature, dissolved in ml of water. made alkaline with 40 percent sodium hydroxide solution and extracted twice with 200 ml of ether. The combined ether extracts are dried over potassium carbonate. liltered. and the ether solution made strongly acidic with a saturated ethereal hydrochloric acid ether solution. The precipitate is collected on filter. washed twice with 50 ml. of anhydrous ether, and dried at 40C/l 25mm. for 5 hours. The dihydrochloride is dissolved in 50 ml. of water. made strongly alkaline with 40 percent sodium hydroxide solution, and extracted twice with 100 ml of ether. The combined ether extracts are dried over potassium carbonate, filtered. and the ether solution made strongly acidic with a saturated ethereal hydrochloric acid solution. The precipitate is collected on a filter, washed twice with 50 ml of anhydrous ether, and dried at 40C/l25 mm. to obtain l-(a-methyl-ptrifluoromethylbenzyl)biguanide dihydrochloride.

EXAMPLE 4 l-(2,6-Dichlorophenyl)biguanide A stirred mixture of 300 g (1.85 mole) of 2,6- dichloroaniline, 155 g. (1.85 mole) of cyanoguanidine and 712 ml of 2.6 N hydrochloric acid (1.85 mole) is treated at 60 C for several hours. The reaction mixture is then cooled, alkylated with 40 percent sodium hydroxide and extracted with 1:1 ether-ethanol. The extract is washed with a saturated saline solution and dried over sodium sulfate. The solvent is evaporated and replaced with benzene which on concentrating results in the crude product. The residue is dissolved in 100 ml of hot methanol and 200 ml of water is added.

The precipitate is removed, washed with water and dried. The hydrochloride salt is then made in alcohol to obtain l-(2,6-dichlorophenyl)biguanide hydrochloride (mp. 236C).

EXAMPLE 5 l-(p-N,NDimethylsulfamylphenyl)biguanide To 11 g (0.055 mole) of p-N.N-dimethylsulfamylaniline is added 17.68 ml (0.055 mole of 3.1N hydrochloric acid. This is heated on a steam bath with 15 ml of isopropanol and 4.62 g (0.055 mole) of cyanoquanidine. The reaction mixture is heated for 18 hours. The alcohol is evaporated off and diluted with 250 ml of 7.4 percent hydrochloric acid. The mixture is filtered, cooled and made alkaline with 10% sodium hydroxide. The precipitate is filtered, triturated with 100 ml of boiling isopropanol and filtered to get l-(p-N,N- dimethylsulfamylphenyl)biguanide (m.p. l90-190.5C)-

EXAMPLE 6 l-(2,4,6-Trichlorophenyl)biguanide hydrochloride To 20 g (0.1 mole) of 2,4,6-trichloroaniline and 10 g (0.1 mole) of cyanoguanidine in 10 ml (0.1 mole) of concentrated hydrochloric acid is added ml of a n-butanol. The reaction 'mixture is refluxed for 17 hours, cooled and the alcohol evaporated off. The residue is extracted with ether after making it alkaline with 40% sodium hydroxide. The ether extract is dried over potassium carbonate and evaporated. The residue is dissolved in methanol, the pH adjusted to about 7, charcoal filtered and evaporated. The residue is triturated with ether and the solid that forms is recrystallized from water to obtain l-(2,4,6-trichlorophenyl)- biguanide hydrochloride (m.p. l7()-l72C).

EXAMPLE 7 l-l3.5-Di(trifluoromethyllbiguanide To 22.9 g (0.1 mole) of 3.5-di(trifluoromethyUaniline and 8.4 g (0.l mole) of cyanoquanidine is added 10 ml of concentrated hydrochloric acid and 20 ml of water. The solution is heated on a steam bath for 1 hour at which time a solid precipitates out. The reaction mixture is cooled to room temperature. made strongly alkaline with 40 percent NaOH and extracted with ether. The ether layer is dried over potassium carbonate. and evaporated in vacuo to obtain an oil. The resimole) of cyanoguanidine is heated at a melt for l /2 hours. The mixture is then cooled, heated with 25 ml of water until solution and then made alkaline with 40 percent sodium hydroxide. The solution is extracted with ether and dried over potassium carbonate and evaporated to dryness. The residue is chromatogramed on silica gel using isopropanol: NH OH to obtain l- (2,3 ,4,6-tetrafluorophenyl )biguanide.

EXAMPLE 9 When the procedures of Examples 1-8 are followed by the starting materials are substituted for those below, then the corresponding product is obtained.

Starting Material .tvdibromoaniline ,3.4-trichloroanilinc 3,5-trichloroaniline -dimethoxyaniline an ne 2,6-dichloro-4-dimethylsulfamido- ,6-dichloro-4-nitroaniline 6 6-dichloro-4-( p-chlorophenyl) 2,6-dichlorobenzylaminc amine dinitroumllne totvtutututqulqw 4-phenylaniline 2,o-dichloro-4'carbethoxyanilinc lo-dicarhethoxyaniline 4-acetoxyhcnzylamine amine aniline p-cyanobenzylamrne 2.6-dittrit'luoromethyl)aniline p-fluoro-a-methylbenzylamine 2,6-dichlorouadimethylhenzylamine p-chloro-a-mcthylbenzylamine o & m-trifluoromethyl-a-methylbenzylamine .6-dii-propylaniline .4-dichloroaniline .4-dibromoaniline ,4-ditluoroaniline .Lditluorounilinc .5-difluoroanilinc due is triturated with 500 ml heptane and the solid which forms is recrystallized from methylene chloride to obtain lI3.5'di(trifluoromethyl)phenyllbiguanide. (mp. l48 149C).

EXAMPLE 8 l-(2.3.4,6-Tetrafluorophenyl)biguanide A mixture of 7.0 g (0.035 mole) of 2,14,6- tetrafluoroaniline hydrochloride and 2.9 g (0.035

S-Irimethoxyaniline ,o-trimethoxyaniline dichloro-A-methoxyaniline .4,5-tetrafluoroaniline o-difluorobenzylamine 6-dibromo-a-methylbenzylamine .t'v-dibromohenzylaminc .4,6-trichlorobcnzylamine 6'dichloro-a-mcthylbenzylamine .4.6arichloro-a-methylbenzydichloro-4-hydroxyamlme .fi-tribromobcnzylaminc ,o-dichloro-4-carhoxyaniline 4( p-chlorophenoxy )anilinc 2.6-dichloro-4-dimcthylamino Product ,o-dibromophenyl J biguanide .3 .4-trichlorophenyl )biguanide .3 ,S-trichlorophenyl )biguanide .6-dichloro-4-nitrophenyl)biguanide 2.6-dimethoxyphenyl )biguanide -2,6-dichloro-4-(p'chlorophenyl)phenyl biguanide l-( 2,6-dichloro-4-dimethylsulfamidophenyl) biguanide 2,6-difluorophenyl)biguanide 2,6-dichlorobenzyl)biguanide 2.6-dibromobenzyl )biguanide 2.4 .-trichlorobenzyl )higuanide 2,6-dichloro-a-methylbenzyl) biguanide l-( ,4.6-trichloro-a-methylbenzyl)biguanide .-dinitrophenyl)biguanide .4. trimethoxyphenyl)biguanide .4. trimethoxyphenyl)biguanide -dichloro-4-n1ethoxyphenyl)biguanide .3 -difluorophenyl )biguanide The following examples are representative of converting one substitutent to another.

EXAMPLE l0 l-(2,6 Dibrom0-4-trifluoromethylphenyl)biguanide To a slurry of 15g (0.06 mole) of p-trifluoromethylphenylbiguanide in 200 ml of water is added dropwise 19.2g (0.12 mole) of bromine over a period of 3 hours. The reaction mixture is cooled and the unreacted bromine discharged with sodium bisulfite. The mixture is made strongly alkaline and extracted into ether. The ether layer is dried over Na- SO charcoaled, filtered and evaporated. The solid residue is recrystallized from dioxane/water to obtain l-( 2.6-dibromo-4-trifluoromethylphenyl)biguanide.

When the procedure of Example 10 is followed but the starting material is substituted for those below. then the corresponding product is obtained.

Starting Material Product and the mixture made alkaline (phl2) with 40% sodium hydroxide. The organic base is extracted into ether, and the ether solution washed with brine, dried (Na SO and evaporated to dryness. The residue is crystallized from aqueous methanol to give l-(2,6- dichloro-4-thiocyanatophenyl)biguanide.

When the procedure of Example 1 l is followed but the starting material is substituted for these below. then the corresponding product is obtained.

l-( 4'trifluoromcthylphcnyl) biguanidc l-( 4-bromophcnyl )biguanidc l-( 2.o-dibromo-4-tritluoromcthylphcnyl )biguanidc l-( 2.4.6-tribromophcnyl )biguanidc l-( 2,o-dibromo-4-t'luorophcnyl) l-[ 4-(4'-chlorophenoxy )phenyll biguanide 1-( 2.4-dichlorophenyl )biguanide phenyl lbiguanide biguanidc l-( 2.4-dichloro-fi-bromophenyl) l-[2.6-dibromo-4-t4-chlorophenoxy) Starting Material l-( 2,-dibromophcnyl)biguanide l-( 2,4-dichlorophenyl )biguanide l-( 2-chlorophenyl )biguanidc l-( 2.4-dibromophenyl )biguanide When chlorine is used in the above example, then the corresponding chlorinated product is obtained.

EXAMPLE ll Starting Material Product I-( 2.6-dibromo-4-thiocyanatophcnyl) biguanide l 2.4-dichloro-6-thiocyanatophenyl) biguanide l-( 2-chloro-4,6-dithiocyunatophenyl) biguanide l-( 2.4-dibromo-(v-thiocyanatophcnyl) biguanidu EXAMPLE l2 l-(4-Nitro-2,6-dichlorophenyl)biguanide l-(2,6-Dichlorophenyl)biguanide hydrochloride (14 g) is added to concentrated sulfuric acid (18 ml) and stirred for 5 minutes. Concentrated nitric acid (Sp. G. 1.5 l )(2.5 ml) is added dropwise, maintaining the temperature between 30 and 40 by water cooling if necessary.

After addition of the nitric acid is complete, the mixture is stirred for 10 minutes, then poured into water.

The mixture is made alkaline with sodium hydroxide, then extracted with ether. The ether extract is washed, dried (Na SO evaporated and the residue crystallized from aqueous methanol to give l-(4-nitro-2,6- dichlorophenyl)biguanide.

When the procedure of Example 12 is followed but the starting material is substituted for those below, then the corresponding product is obtained.

Product l-(4-trifluoromethylphenyl) biguanide l-(4-bromophenyl)biguanide l 2-iodophenyl)bi uanide l 4-chlorophenyl) iguanide l 4-iodophenyl)biguanide l l-(2.6-dichloro-4-nitro=a-methylbenzyl) biguanide l-( 2,6-d ibromo-4-nitrophe nyl )biguanide l-[.2,6-dinitro-4-( p-chlorophenyl )phenyl] biguanide 17 EXA M PLE l3 l-(2,6-Dibromophenyl)biguanide hydroiodide A solution of l-(2,6-dibromo-4- ether (150 ml) with stirring. l-(2.6- dibromophenyl)biguanide hydroiodide is obtained.

EXAMPLE l4 Ten thousand tablets for oral use, each containing 50 mg of l-(2,6-dichlorophenyl)biguanide hydrochloride. are prepared from the following types and amounts of material:

Ingredient Grams l-(2.6-dichlorophenyl)biguanide hydrochloride 500 Lactose U.S.P. 350 Potato Starch U.S.P. 346

The mixture is moistened with an alcoholic solution of 20 grams of stearic acid and granulated through a sieve. After drying, the following ingredients are added:

Ingredient Grams Potato Starch U.S.P. 32(1 Talcum 400 Magnesium Stearate 500 Colloidal Silicium Dioxide 64 The mixture is thoroughly mixed and compressed into tablets.

EXAMPLE 15 Ingredient Grams l-( 2.4,6-trichlorophcnyl )biguanide hydrochloride 7.5 Ascorbic acid 1 Sodium bisulphite 0.5

Sodium sulphite The previous ingredients are added to distilled water. diluted to 1 liter of solution and thoroughly mixed. The solution is used to fill ampoules which are sterilized hot in the usual way.

EXAMPLE 16 An elixir in which each ml contains 50 mg of l-(ptrifluoromethylphenyl)biguanide hydrochloride is prepared by diluting 750 ml of invert sugar with 100 ml of water and adding to this 0.3 g of benzoic acid and g of l-(p-trifluoromethylphenyl)biguanide hydrochloride. 100 ml of alcohol (U.S.P.) containing 0.2 g of fla- 18 vors is added and water is added to a total volume of 1 liter. The solution is thoroughly mixed. filtered. and bottled.

Example 17 The ingredients are thoroughly mixed with each other and the mixture is filled in gelatin capsules. Each capsule contains 500 mg of the composition and thus 150 mg of l-(2,6-dichloro-a-methylbenzyl)biguanide hydrochloride.

Example 18 Tablets are prepared as follows: 100 g of l-(2.6 dibromophenyl)biguanide hydrochloride.

20 g of corn starch. 14 g of calcium carbonate. and

l g of magnesium stcaratc.

The active compound and the starch are thoroughly mixed, moistened with a 10 percent gelatin solution, and granulated by pressing through a No. 20 sieve. The

) granules are dired, thoroughly mixed with calcium carbonate and magnesium stearate, and compressed into tablets, each weighing about 125 mg and containing 100 mg of l-(2,6-dibromophenyl)biguanide hydrochloride.

Example l9 Composition:

g of l-(2.6-dichlorophenyl)higuanide hydrochloride 50 g of microcrystalline cellulose. H) g of polyvinylpyrrolidine.

5 g of magnesium stearate. and g of starch.

The active compound and cellulose are intimately mixed, moistened with a polyvinylpyrrolidine solution in water, and granulated by pressing through a No. 10 sieve. The dried granules are mixed with starch and magnesium stearate and are compressed to drages cores, each weighing 225 mg. The cores are now provided with an elastic subcoat of an aqueous sugar solution containing 60 g of powdered acacia, 60 g of powdered gelatin, and 600 g of sugar per liter of solution. Thereafter a dusting powder mixture of g of powdered sugar. 60 g of powdered starch, l g of powdered talc, and l g of powdered acacia is applied to the dragee cores. Coating with the gelatin subcoat and dusting are repeated about five times. The thus treated cores are sugar coated in the coating pan with a 60 percent sugar solution. Sugar coating is repeated until each dragee weighs about 400 mg.

Example 20 Composition:

50 g of l(2,6-dichloro hen l)bi uanide hydrochloride, 200 g of magnesium hy roxi c gef. Y 200 g of aluminum hydroxide gel. 240 g of sorbitol.

[0 g of methyl p-hydroxybenzoate. and

(4.5. 5000 cc. of distilled water.

p The ingredients are intimately dissolved and suspended in the distilled water. Flavoring agent may be' Example 21 50 g of l-(p!rifluoromethylphenyl)higuanide acetate,

g of propyl p-hydroxyhenzoate are dissolved and diluted to 5000 cc, with twice distilled water after the addition of modified Sore nsen buffer solution in an amount sufficient to adjust the pH- value to a pH of 6.0. Sodium chloride is dissolved therein in an amount sufficient to render the resulting solution isotonic. The final solution is passed through a bacteriological filter and the filtrate is autoelaved at 120C for minutes to yield a parenterally applicable solution which contains 50 mg of l-(p-trifluoromethylphenyl)biguanide acetate in 5 cc.

We claim:

I. A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals which comprises orally or parenterally administering thereto betwen 0.5 mg/kg 70 mg/kg per day of a compound of the formula where:

R and R are chloro or bromo and 'R is p-chlorophenyl or p-chlorophenoxy. and

a non-toxic acid addition salt thereof.

2. A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals which compries orally or parenterally administering thereto between 0.5 mg/kg 70 mg/kg per day of a compound of the formula NH NH II II R4 NH-C-NH-C-NH2 where:

R and R are chloro fluoro or bromo and R is halo or trifluoromethyl; and

a non-toxic acid addition salt thereof.

3. The method of claim 2 wherein R and R., are chloro and R is trifluoromethyl thus administering l- (2,6-dichhloro'4-trifluoromethylphenyl)biguanide.

4. The method of claim 2 wherein R R and R, are chloro thus administering l-(2.4,6-trichhlorophenyl)- biguanide.

5. The method of claim 2 where R: and R are bromo and R is trifluoromethyl thus administering l-(2.()- dihromo-4-trifluoromethylphenyl)biguanide.

6. The method ofclaim 2 for the treatment ofduodenal ulcer and peptic ulcer.

7. The method of claim 2 wherein R R and R are bromo thus administering l-(2,4,6-tribromophenyl)- biguanide.

8. The method of claim 2 where R and R are bromo and R is fluoro thus administering l-(2,6-dibrom0-4- fluorophenyllbiguanide.

9. The method of claim 2 where R and R are bromo and R is chloro thus administering l-(2,6-bromo-4- chlorophenyllbiguanide.

10. The method of claim 2 where R and R are chloro and R is bromo thus administering l-(2,6- dichloro-4-bromophenyl)biguanide.

11. The method of claim 2 where R and R are bromo and R is iodo thus administering l-(2,6- dibromo-4 -iodophenyl)biguanide.

12. The method of claim 2 where R and R are chloro and R is bromo thus administering l-(2,4- dichloro-o-hromophenyllhiguanide.

13. A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals which comprises orally or parenterally administering thereto between 0.5 mg/kg mg/kg per day of a compound of the formula R NH NH ll llv R NH-C-[NH-C-NH where:

R and R are halo and R is nitro; and

a non-toxic acid addition salt thereof.

14. The method of claim 13 where R and R are chloro thus administering l-(2,6-dichloro-4- nitrophenyl )biguanide.

15. The method of claim 13 where R and R are bromo thus administering l-( 2,6-dibromo-4- 

1. A METHOD OF TREATING GASTROINTESTINAL HYPERACIDITY OR ULCERATION IN HUMANS AND MAMMALS WHICH COMPRISES ORALLY OR PARENTERALLY ADMINISTERING THERETO BETWEEN 0.5 MG/KG - 70 MG/KG PER DAY OF A COMPOUND OF THE FORMULA
 2. A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals which compries orally or parenterally administering thereto between 0.5 mg/kg - 70 mg/kg per day of a compound of the formula
 3. The method of claim 2 wherein R2 and R6 are chloro and R4 is trifluoromethyl thus administering 1-(2,6-dichhloro-4-trifluoromethylphenyl)biguanide.
 4. The method of claim 2 wherein R2, R4 and R6 are chloro thus administering 1-(2,4,6-trichhlorophenyl)biguanide.
 5. The method of claim 2 where R2 and R6 are bromo and R4 is trifluoromethyl thus administering 1-(2,6-dibromo-4-trifluoromethylphenyl)biguanide.
 6. The method of claim 2 for the treatment of duodenal ulcer and peptic ulcer.
 7. The method of claim 2 wherein R2, R4 and R6 are bromo thus administering 1-(2,4,6-tribromophenyl)biguanide.
 8. The method of claim 2 where R2 and R6 are bromo and R4 is fluoro thus administering 1-(2,6-dibromo-4-fluorophenyl)biguanide.
 9. The method of claim 2 where R2 and R6 are bromo and R4 is chloro thus administering 1-(2,6-bromo-4-chlorophenyl)biguanide.
 10. The method of claim 2 where R2 and R6 are chloro and R4 is bromo thus administering 1-(2,6-dichloro-4-bromophenyl)biguanide.
 11. The method of claim 2 where R2 and R6 are bromo and R4 is iodo thus administering 1-(2,6-dibromo-4 -iodophenyl)biguanide.
 12. The method of claim 2 where R2 and R4 are chloro and R6 is bromo thus administering 1-(2,4-dichloro-6-bromophenyl)biguanide.
 13. A method of treating gastrointestinal hyperacidity or ulceration in humans and mammals which comprises orally or parenterally administering thereto between 0.5 mg/kg - 70 mg/kg per day of a compound of the formula
 14. The method of claim 13 where R2 and R6 are chloro thus administering 1-(2,6-dichloro-4-nitrophenyl)biguanide.
 15. The method of claim 13 where R2 and R6 are bromo thus administering 1-(2,6-dibromo-4-nitrophenyl)biguanide. 